1. Field of the Invention
The invention is directed to the use of polyhydroxyalkylamine-N,N-dicarboxylic acids as builders in detergents and cleaning agents.
2. Discussion of the Background
The good detergency and cleaning capability of modern synthetic detergents is known to be due in large measure to their high content of sodium phosphate. Because of the hazard of eutrophication of surface waters, phosphates are being questioned from an environmental standpoint, and a progressive replacement of phosphates in detergents by substances which pose a lesser environmental threat has been required. The particular substitutes which have been employed include, most importantly, nitrilotriacetic acid, citric acid, polycarboxylic acids, and gluconic acid, as well as polymeric acids such as, e.g., polyacrylic acid, maleic acid copolymers, and polymaleic acid (see 1975 Angew. Chem., 87, 115).
A major development is the use of inorganic waterinsoluble builders of type zeolite A (see Ger. AS 24 12 837) which are considered excellent in environmental safety but which do not provide adequate support for the washing action of the surfactants, and can only be used in combination with one of the abovementioned organic builders as a phosphate substitute.
Thus it is seen that there is still no phosphate substitute for use in detergent formulations which has characteristics parallel to the excellent combination of characteristics of sodium triphosphate as a builder.